A bumper cross-beam comprises generally vertical front and rear walls, which play respectively the role of compressive strut and tensile strut in case of collision and which are spaced apart thanks to transverse or flanking walls. These flanking walls are usually horizontal upper and lower walls. Bumper cross-beams are often profiles advantageously extruded from an aluminium alloy, comprising a hollow section member with at least a chamber delimited by the said vertical front and rear walls and horizontal upper and lower flanking walls. Bumper cross-beams are designed such that the force at which they begin to plastically deform is lower than the force necessary to irreversibly deform the vehicle structure. In the case of a minor collision, only the bumper cross-beam is deformed with the result that this sole part has to be replaced. In the past, deformation elements, also called “crash-boxes”, have been proposed to increase the maximum force of impact at which there is still no plastic deformation of the vehicle structure. Located between the cross-beam and the vehicle structure (e.g. its longitudinal beams), they are further used as attachment means. They are designed to be plastically deformed as soon as the kinetic energy of the vehicle at the time of the collision is higher than a critical value. Their plastic deformation is advantageously a progressive folding, which absorbs at least partially the energy of impact. The deformation elements are usually in the form of hollow section profiles, generally multi-chamber hollow section profiles, whereby their longitudinal axis lies in the direction of the longitudinal axis of the vehicle.
The U.S. Pat. No. 7,401,825 describes a bumper with an attachment member to be made thereon for the purpose of mounting the bumper onto longitudinal beams of a vehicle, such that section walls acting as compressive and tensile struts and a pair of flanking walls joining them form a hollow section. The attachment member is in the form of a hollow section exhibiting at least one side wall and two transverse walls following on therefrom with a length of hollow section with the longitudinal beam. The hollow section is in the form of a push-fit length matching the inner cross-section of the longitudinal beam. The other end region of the attachment member is provided with collar-type parts projecting from their end edges and aligned approximately parallel to the transverse walls.
German patent application DE 10 2008 022 564 describes a cross beam fastened to body components of a motor vehicle body by supporting elements i.e. absorber element. The cross beam is fastenable to the supporting elements at two retaining positions and/or the supporting elements are fastened to the body components of the body in the retaining positions. The supporting elements comprise a respective retainer for the cross beam, where the retainer is formed by upper and lower bars. The supporting elements are formed from extruded sections or from metal sheets.
There is an increasing need for assembling various additional parts like for example an energy-absorbing element, a pendulum-stopper, an additional energy-absorbing-element for Pedestrian-impact, a radar-sensor; an acceleration-sensor, a horn, module-carriers, supports for fascia, in the front part of the cross-beam.
Traditionally these additional parts are added via cut-outs or holes in the cross-beam and blind rivets nuts. However this solution locally affects the properties of the cross-beam and deteriorates the force intrusion properties. Moreover this necessitates a separate step to drill the holes and a separate step to implement the rivets which increase cost and process length.
Therefore there exists a need for providing means for assembling additional parts in the front part of the cross-beam, without affecting the properties of the cross-beam and deteriorating the force intrusion properties.